Mandarin Characters

My computer won't show the Mandarin characters. It may be missing something since instead of the characters it shows a box, a square for pretty much every character. I'm using a relatively old Dell Latitude D510 running Windows XP Professional. Is anyone aware of something I can download, or something I can do, so that I can see these characters and can start learning some Mandarin?

If the link doesn't work, just go to the Memrise's MAIN forums page (right now you're in the forms page for the Mandarin language, you want to go to the forums page that's accessible from your homepage when you sign-in to Memrise), scroll down and look for the thread entitled "Mandarin Characters on old computer." There I posted my same concern, someone provided me with a lead, and it was what eventually led to me solving my problem.